- Add check in task.copy() to preserve NOT_SPECIFIED context value
- Previously, NOT_SPECIFIED was being converted to None during copy
- This affected kickoff_for_each and kickoff_for_each_async methods
- Add comprehensive tests covering NOT_SPECIFIED, list, and None contexts
- Rename import 'copy' to 'shallow_copy' for clarity
Co-Authored-By: João <joao@crewai.com>